Branson spaceship explosion: The 'missed' warnings

Sir Richard Branson's space tourism company Virgin Galactic has been accused of ignoring a series of warnings that its $500 million rocket was unsafe for flight.

A number of senior aerospace engineers repeatedly voiced fears over the design of Sir Richard’s SpaceShip Two and the safety protocols surrounding its testing.

The Telegraph has seen emails and other documents in the public domain — dating back several years, and as recently as last year — in which the engineers warned of the dangers of Virgin Galactic’s rocket engine system.

It also emerged on Saturday that three senior Virgin Galactic executives — the vice-president in charge of propulsion, the vice-president in charge of safety, and the chief aerodynamics engineer — had all quit the company in recent months.

The Virgin Galactic spacecraft, which was scheduled to begin passenger flights early next year, blew up in the sky above the Mojave Desert in California during a test flight on Friday.

The incident, in which one pilot died and another was seriously injured, puts in jeopardy Sir Richard’s dream of space travel for passengers, each paying $250,000 (£156,000).

The dead pilot was named as Michael Alsbury, an experienced American test pilot.

His widow, Michelle Saling, said: “I have lost the love of my life. I am living in hell right now.”

Scaled Composties, the US aerospace company which employed the pilots, said Mr Siebold has been "alert" and talking with his family and doctors.

Virgin Galactic, in an attempt at damage limitation, initially dismissed the explosion as an “anomaly”. However, aerospace experts insisted that it had been a disaster waiting to happen.

Tom Bower, an investigative journalist and Sir Richard’s biographer, described the crash as “predictable and inevitable”. He said: “It’s a very crude rocket.”

Sir Richard arrived at the crash site on Saturday insisting that “safety has always been our number one priority”. He admitted that only if the problems that caused the crash could be overcome would the programme continue.

The Telegraph can disclose that Sir Richard’s company, as well as US authorities, were warned about safety issues on numerous occasions, as long ago as 2007 when three engineers died in an explosion during testing of a rocket engine on the ground.

Carolynne Campbell, the lead expert on rocket propulsion at the International Association for the Advancement of Space Safety (IAASS), said: “This explosion is not a surprise. None whatsoever, I am sorry to say. It is exactly what I was expecting. It was Russian roulette which test flight blew up.”

She had first warned Virgin Galactic about the danger of its nitrous oxide-propelled engines in the aftermath of the 2007 disaster, and has repeated those warnings since.

In a study published in 2010 on her website and sent to Sir Richard’s company as well as to the US authorities, she wrote: “We are not confident that … we yet know enough about N2O [nitrous oxide] to consider it a safe oxidiser for use in passenger flight.

"In the light of what we do know, safety must remain a major concern.”

In the study, she questioned Virgin Galactic’s claim on its website that its rocket system was “benign” and “stable”.

In emails sent by Geoff Daly, a US-based British rocket scientist, to officials at the Federal Aviation Authority (FAA) last year, he warned of another disaster if test flights were given the go-ahead.

At the time, Virgin Galactic had planned to begin its first passenger flights in December 2013, although the date of the inaugural flight had been repeatedly postponed.

In the emails, published on a US government website, Mr Daly wrote on July 13 2013: “We respectfully request a response from you on what actions the FAA will be taking with respect to the permit issued and the operations as planned in the Mojave and New Mexico facilities.

"Remember three people have been killed and numerous persons injured by a prior explosion involving N2O in this motor design. We do not need another incident on the ground/flight line or in the air.”

In another email — this time to the US Chemical Safety Board and sent on July 17 2013 — Mr Daly wrote: “Sir Richard Branson, his two children, Justin Bieber [the singer] and one other will be the first passengers to fly into space during this coming December 2013, and everyone realises there is a problem, even the engineers …have said so off the record.”

Tomasso Sgobba, executive director of IAASS and the former head of safety at the European Space Agency, said that Virgin Galactic had refused to share information with industry experts outside the company and declined to have its rocket design peer-reviewed.

Representatives of Virgin Galactic had refused to come to IAASS meetings, he said.

“They operated in secrecy, which is difficult to understand,” said Mr Sgobba. “They don’t use modern techniques in putting safety into the design.

"They use outdated methods like testing and then seeing what happens. There has been no independent oversight.

"There is no peer review. I have been saying for some years now this was an accident waiting to happen.”

Mr Bower, who exposed the safety concerns surrounding the project in his biography of Sir Richard published earlier this year, said: “What happened yesterday was very sad for the pilot obviously but it was predictable and inevitable.

“All the engineers in California working on the project I’ve spoken to said it was very dangerous.”

US investigators on Saturday began examining the wreckage to determine what went wrong.

One area of focus will be claims that the test pilots had requested a two-hour delay in take-off due to concerns over the temperature of the nitrous oxide in the fuel tanks.

SpaceShipTwo was being tested ahead of a possible passenger launch in March. It was the first test flight using a different hybrid fuel system.

In May this year, the company and its partner firm Scaled Composites said they would switch from using a rubber-based solid fuel burned in a stream of nitrous oxide, which had caused engine instabilities in earlier test flights, to a plastic-based solid fuel called thermoplastic polyamide also burned in nitrous oxide.

It was claimed the new fuel would be more reliable and more powerful.

In a statement on its website on Friday, the company said: “During the test, the vehicle suffered a serious anomaly resulting in the loss of the vehicle.”

A spokesman for Virgin Galactic said: “The investigation of the accident is now in the hands of the National Transportation Safety Board (NTSB) and we are not permitted to make any comment whatsoever until that investigation has run its course.”

The NTSB investigation is its first involving a manned spacecraft. It was unclear if there was a “black box” flight recorder.